Sander



April 16, 1940- c. A. CAMPBELL Er AL 2,196,977

SANDER Filed June 21, 1957 :5 sheets-sheet 1 Gttornegs April 15, 1940.c. A. CAMPBELL ET AL .2,196,977

SANDER Filed June 21, 1937 3 Sheets-Sheet 2 April 16, 1940.

c'. A. CAMPBELL Er A1.

SANDER Filed June 21, 1937 3 Shets-Sheet 3 (Wm/Leva @.@m/mpbe/ 3g u.MGZ@ (lttornegs Patented Apr. 16, 1940 PATENT OFFICE SANDER Charles A.Campbell and Lewis A. Safford, Watertown, N. Y., assignors to The NewYork Air Brake Company, a corporation ot New Jersey Application June 21,1937, serial No. 149,493

21 Claims.

This invention relates to sanding devices for railway vehicles, andparticularly yto sanding mechanisms intended for use with modern highspeed trains.

The high speeds characteristic of stream-lined light weight trains haveintroduced a serious braking problem. The stopping distance must be keptwithin limits heretofore attained with slower trains in order to permitoperation of the high speed trains with the existing signal spacing. Toattain this result it is necessary to apply the brakes with an intensitywhich approaches the maximum permissible. In fact the brakes arecontrolled in response to the deceleration rate so that the initialapplication is severe, the brakes being gradually released by adecelerometer to maintain a substantially uniform deceleration rateuntil the train is brought nearly to rest, at which time the brakes arefurther released to permit a smooth stop.

In operating the brakes under such conditions the danger of loclnng awheel and causing it to slide is substantial. If a wheel locks it cannotvbe released in time to prevent serious injury to 'the wheel. If railconditions were uniform the operation of the brakes could bestandardized with a safe margin, but rail conditions aresubject to widevariations because of rain, snow, sleet and various other uncontrollablefactors. 'Ihe effects of rail conditions on brake performance are sogreat that a brake system which operates satisfactorily, and with a safemargin, under favorable rail conditions, may slide wheels under evenmoderately adverse rail conditions.

The problem therefore is to standardize the condition of the rail sothat the variations encountered will be within the safe working limitsof the brake system if set for good rail conditions.l

fore the braking pressure reaches a value which could cause sliding.

In sanding devices as heretofore used, the sand has been caused totrickle down a pipe impelled by a comparatively feeble jet of air. Thisis slow and often ineffective. With a train operating at 110 miles perhour, and with the possibility of cross winds, some more rapid andcertain Way of insuring the entrance of the sand between the wheels andthe rail is vitally necessary. Accord- 5 ingly, one of the features ofthe present invenvtion is the provision of means to blow the sandviolently into the angle between the wheel and the rail, so violentlythat it is certain to arrive at the intended point of application.

To accomplish this result it is desirable to operate the sand traps andsander pipes under substantial pneumatic pressures, and since it isundesirable to operate the sand boxes under such pressure, an importantfeature of the present invention is an intercepter valve, which uponinitiation of the sanding operation, disconnects the sand trap from thesander box.

This idea of pressure sanding has another very important aspect which isthat the sandervnozzles are exposed and are likely to become clogged,particularly by mud, sleet or snow. An important feature of the presentinvention is the use of a distensible sander nozzle so designed that itwill be markedly deformed under the sanding pressure used, and willserve to break away any obstructions, particularly ice or sleet.Distensibility has peculiar significance with the use of sandingpressures suflicient to produce substantial distension even when thenozzle is heavily coated with ice.

Another important feature of the invention is the arrangement of theports in such a way that any sanding operation, whether it is initiatedmanually or automatically by the operation of the brake, will occursimultaneously in advance of every braked wheel. Means are provided topermit certain sanding units to be cut out if desired. For example,under favorable rail conditions it might be desirable to permit sandingunder the leading wheels only.

For the reason that most stream-lined trains are operated in onedirection, it is not ordinarily necessary on such trains to provideselective sanding according to the direction of travel. It 5 is wellknown, in the sanding art, to provide such selective sanding,controlled, for example,l by the reversing mechanism of the propellingunit. Such a device is applicable to the present invention by theadoption of means such as that de- 50 scribed in the patent to Schaake758,194, April 26, 1904,l but this is not regarded as a feature of thepresent invention and hence need'not be illustrated. The system of v thepresent invention obviously can be so used.

The preferred embodiment of the invention will now be described inconnection with the accompanying drawings, in which- Fig. 1 is adiagrammatic view, chiefly in section,

n showing the sander control mechanism for the train and the sandermechanism for one wheel.

Fig. 2 is a diagram showing the control connections for sandersthroughout a train.

Fig. 3 is a vertical section of a sand trap constructed according to thepresent invention a'n showing its actual construction. f

Fig. 4 is a view half in elevation and half in section, of the sand trapshown in Fig. 3, the plane of section passing through the axis of stem83 of the interceptingvalve.

Referring rst to Figs. 1 and 2, any suitable source of air underpressure is represented by the reservoir 6, assumed to be the mainreservoir of the air brake system and 1 represents pipes directlyconnected thereto. s

Control of sanding is eiected by the sander valve generally indicated bythe numer 8 applied to its body. This valve is substantially identicalin structure, and identicalin function with that shown in the patent toCampbell 2,035,533, issued March 31, 1936. Reference may be made to thatpatent for details, and since the valve is illustrated here merely astypical control means, a brief description will suice.

A branch of pipe 1 leads to body 8, and a pipe 9 leadsI f rom the bodyto the motor chamber II of the sander switch whose body is indicated atI2. A timing reservoir I3 is connected with body 3 by pipe I4. A pipe I5leads to body 8 from a brake valve (not shown) which in certainapplications, for example emergency applications, supplies air underpressure to the space above piston I6. Piston valve I1 may be forceddownward by this means or by hand button Iii.v

The sander control valve in body 8 is shown in Fig. 1 in normal(inactive) position. At such time the pipe 9 is vented to atmospherethrough the choke I9 with which it is constantly in communication. andsince the supply port 2! in valve housing 8 is blanked by the lower headof the piston valve I1, the space II below the motor piston of thesander switch is at atmospheric pressure.

'Iiming reservoir I3 is charged from pipe 1, past the reduced middleportion of valve I1 to pipe I4. Ii.' the valve I1 be moved downwardeither by the piston I6 or by the button I 9 the main reservoirconnection 1 is blanked and the timing reservoir I3 is connected throughpipe I4 and the reduced middle portion of valve I1 with theport 2l. Thissupplies air above a piston 22 which overpowers the return spring 23 sothat the valve I1 remains in its lower position until timing reservoirpressure bleeds away through the choke I9. It should be explained that abranch of port 2I leads around the lower head of valve I1 to the pipe 9and choke I9. Conseouently, the effeet of depressing the button I8 orthe piston I 6 is to admit pressure uid to the space below vthe motorpiston of the sander switch and to maintain this pressure for a time.determined by the capacity of choke I9 and the volume of the timingreservoir I3. When pressure in the timing reservoir is substantiallydepleted spring 23 willrestore the valve to normal position.

Ii' timed sanding is not desired, manuallvcontrolled sanding can be hadb v depressing the button 24 which unseats the valve 25 and allows mainreservoir air to ow via pipe 1 past the reduced portion vof valve I1,passage 26, valve 2l, and passage 21. to the branch of port 2|, and viapipe 9 to the space II. As long as button 24 is held depressed thesanding switch will be energized. 'I'hus the control valve, generallyindicated at 6, provides for timed sanding say for sixty seconds. Thismay be manually initiated by depressing button I3 or may beautomatically initiated by a brake application through the operation ofthe piston. I6. Sanding at will may be secured by depressing the button24 and will continue as long as the button is held depressed and thereis sand in the traps.

Referring now to the sander switch. The development of pressure in themotor chamber II below the piston 23 forces this up against the re"-sistance of the coil springs 29 causing a contacter head 3| to bridgethe contacts 32 and 33. This energizes a sander circuit, represented bythe battery 34 and the wires 35 and 36, which, as indicated in Fig. 2,extend throughout the train. The switchv 31 may be provided to cut outthe rear sanding units of the train, if desired, but the normal positionof the switch 31 is closed so that all the `sanders throughout the trainwill operate simultaneously.

The leading sanding unit on the train will now be described withreference to Fig. 1

. Connected between the wires 35 and 36 for- A ward of the switch 31,and hence not subject to y control thereby, is solenoid winding 33. Whenthis winding is energized its armature is forced downward to close andexhaust poppet valve 39 and open an inlet poppet valve 4I controllingflow from main reservoir pipe 1. This motion is resisted by a coilcompression spring 42. In a normal position, shown in Fig. 1 (winding 33deenergized) valve 4I interrupts the supply of air from the mainreservoir pipe 1 to branch pipe 43, and valve 39 vents branch pipe 43 toatmosphere.

When the solenoid is energized and the vent is closed, main reservoirair is admitted to the pipe 43. Pipe 43 leads to the space below the mitsupplemental or cleaning air at high pressure and in large volume to thesand trap but only for a brief period. The clean out pipe connection isindicated at 52 and the clean out timing valve comprises a diaphragm 53subject on its lower face to pressure in chamber 49 and subject on itsupper side to the pressure oi' a coil compression spring54 assisted bythe pressure in chamber 55 within cap or housing 56. There is a chokeconnection 51 from the space 49 to the chamber` 55. When pressure isadmitted beneath diaphragm 44 valve 41 is unseated, and main reservoirpressure is immediately established in the chamber 49 but not. in thechamber 55 because of the delaying action of the choke 51. It followsthat diaphragm 53 moves upward and then as pressure is equalized throughthe'choke 51 moves downward. Diaphragm 53 servesas a valvevinconjunction with the annular seat 53, to control flow to the clean outpipe 52. It follows that when pressure is .established in the chamber 49ber 65 separated by the inclined partition 66 ex cept for opening 69.Sand supplied through the pipe 62 flows downward through the combineddistensible approach 61 and valve seat 88 into the upper chamber 84 -andthence through port 69 to the lower chamber 65 where it accumulatesbehind a dam or crest 1i over which the sand must flow to enter thenozzle pipe 12. The nozzle pipe 12 leads to a fitting 13 on which ismounted a distensible nozzle 14 formed of resilient rubber or likematerial. This directs the discharging sand into the angle between thetread of the related wheel and the top 16 of the rail. The distensibleapproach 61 and the valve seat 68 are also formed of resilient rubber orsimilar material, and are held in place by a fitting 11 whose whichA theportion 61 Ymay be expanded or disl tended.

When the sander is out of action, said flows through the pipe 62 throughthe valve seat 68 into the upper chamber 84 from which it flows throughthe passage 69 into the lower 'chamber 65. Flow is arrested by the dam1| at the angle of repose of the sand, so that between operations of thesanding device the sand trap receives the entire charge of sand to beused in the succeeding sanding operation.

The sanding jet pipe 5| leads to a passage 19 in which is mounted asmall jet nozzle 8|. This delivers a jet of air beneath the partition 66and substantially parallel thereto. v The jet stirs up the sand in thechamber 65 during the sandingr operation. The eect of this is to causethe sand to ow over the crest 1i where it enters the iniiuence of asecond jet controlled by nozzle 8,2 and directed down the pipe 12. Thenozzle 82 is screwed on to the lower end of a hollow stem 83 whichpasses through the passage 19 and is ported at 84 to communicatetherewith so that when air is supplied to the pipe 5i it ows to both thejets 8| and 82. It also flows upward through an axial bore 85 into aflattened bulb 86 secured to a flange on the uppery end of the'stefn 83by a nut 81 and bearer plate 88. A cup-like. valve element 89 is mountedover the bulb 86 and when this bulb is inflated the valve 89 yis movedupward to seal against the seat 68. Consequentlv when the sander comesinto operation. the supply of sand is intercepted at the seat 88.

If the intercepting of the sand were all that were required -arelatively simple problem would be afforded, but it is necessary notonly to intercept the sand but to produce an air-tight seal so that ifsubstantial pressure is developed in the sand trap the sand boxes willbe protected against backr flow. Sand flowing down through the approach61 has a tendency to arch and resist closure of the valve 89. Thisrtendency, however, is defeated by the distension of the approach 61 intothe space 18. In other words. the distensible approach offers-apocketinto which edly that the obstruction is blown clear.

sand is forced to permit complete closure and air tight'seating of thevalve.

The clean out air 52 vis delivered directly to the upper chamber 84 ofthe sand trap, entering adjacent the fitting 11 and is also delivered byway of the bypass 9| to the space around the nozzle 82. Thisspace is indirect communication with the lower chamber 65.

It follows that when the valve 41 is unseated air jets are delivered atthe nozzles 8i and 82, the sand supply is intercepted at the valve seat88 and a tight air seal is there produced. Air in large quantity is alsodelivered to both chambers of the trap and to the nozzle 14 for a shortperiod. If the nozzle 14 is clogged by mud, ice, snow or sleet, it willbe subject suddenly to'heavy internal pressure and will be distended somark- If the sander nozzle is clearthe development of pressure withinthe sand trap and the nozzle will be less marked. In any case the sandwill be delivered by a rapidly owing jet into the angle between thetread of the wheel and the rail.

Referring now to Fig. 2, the arrangement of the sanding units, otherthan the leading one, will be explained. The essential difference isthat thesey Sanders do not derive their operating air directly from themain reservoir. It is not ordinarily convenient to run a main reservoirpipe throughout the entire length o'f the train. but there usually is abrake pipe or supervisory line which is normally charged to mainreservoir pressure or to a pressure slightly lower. Such a brake pipe isindicated in Fig. 2 at 92.

For each sanding unit there is a small reservoir 93 which may, forexample, be fed from the brake pipe through a check valve 94 and a flowrestricting choke 95, the purpose of the flow restricting choke being toprevent derangement of the braking system by the demand of the sandingsystem for air. This scheme is merely representative of any local sourceof sanding air. So far as the present invention is concerned it is.immaterial how the air is supplied.

As indicated in Fig. 2, the remainder of the sanding equipment on thevarious cars is identical -with that shown in Fig. 1. Similar referencenumerals, with the distinguishing letters a and b, are used todistinguish the second and third units from the leading units previouslydescribed. While only three units are shown in Fig. 2, and while onlythe leading wheel of the truck is shown, it will be understood that thesanding apparatus is repeated throughout the entire length of the train,and every braked wheel or at least the leading Wheels of every truck aresanded.

The operation of the device has been explained as the descriptionproceeded, and only a brief recapitulation is needed.

Operation of any of the instrumentalities associated with the sandervalve 8 causes energization ofthe sander switch I2 to close the circuit,energizing the windings' 38, 38a, 38h, etc., simultaneously. The effectof this is to deliver air through the jet pipes 5I, Sia, 5Ib, andsimultaneously through the clean out pipes 52, 52a, 52h, of the Sanders.The effect is to start the jets into operation and isolate the sandtraps from the sand boxes. Then if any nozzle 14, 14a, 14h isobstructed, the immediate development of high pressure will clear theobstructed nozzle. At this and at any nozzle which is not obstructed,rapid delivery of sand to the rail will occur and will continue untilthe sand in the traphis exhausted unless sooner terminated by sure inthe pipe 5| (or ila or Mb), will be disslpated and the correspondingintercepting valve loY will move to its lower position permitting itstrap to be recharged with sand.

The invention has been described in considerable detail, but thedescription is intended to be illustrative and not limiting.

What is claimed is:

1. 'Ihe combination of a sand trap or the like and a sand interceptingvalve adapted to seal air tight said valve 'comprising valve elementsrelatively movable toward and from one another,

at least one of said elements being resilient and affording adistensible pocket into which sand trapped between the valve elementsisV forced during closing movement of the valve, to an extent suiiicientto permit tight closure of the valve elements.

2. The combination of a sand trap or the like and a sand interceptingvalve, said valve comprising a resilient rubber-like valve seat member.having a distensible 'tubular walled approach passage; means forsustaining said seat while leaving the walls of said approach passagefree to expand; and a valve movable toward and from said seat, thedistension of the approach passage. when sand is compacted by closingmovement of theV valve serving to permit retrogradel movement of thesand and tight closure of the valve.

3. The combination of a sand trap or the like and a sand interceptingvalve, said valve comprising a valve seat member; a distensible conduitforming member leading thereto; and a valve movable toward and from saidseat, the distensibility oi said conduit member serving to relieve thearching tendency of the sand and thus permit complete closure of thevalve.-

4. The combination of a source of sand; a sand trap normally incommunication with said source and arranged to receive a charge of sandby gravity ilow therefrom, said trap including a duct through which thetrap may discharge sand to a point of use and sand feeding jet meanssubstantially alined with said duct; means for supplying air underpressure to said iet means to discharge sand through said duct; andpressure operated means rendered eilective by the supply of such air toseal the trap from said source.

5. 'Ihe combination of a source of sand; a sand trap normally incommunication with said source and arranged to receive a charge of sandby gravity flow therefrom, said trap including a normally inactive ductthrough which sand may be propelled against the action of gravity to apoint of use, and sand propelling jet means substantially alined withsaid duct; means serving to isolate said trap from said source; andmeans serving to operate the last named means and substantiallysimultaneously supply pressure iluid to said jet means to causedischarge of sand from the trap through said duct.

6. 'I'he combination of a sand trap arranged to be operated undersubstantial pneumatic pressure during the sanding operation, said trapincluding sand-feeding jet means; means for supplying pressure fluid tosaid trap and jet means; and a sanding nozzle arranged to-be i'ed bysaid trap and subject to pressure in the trap, said nozzle beingdeformable by the pressure used to operate the trap. and the parts beingso arranged that the nozzle will be deformedand tend to clear itself atleast ii the trap is under operating pressure and ilow vthrough thenozzle is l materiallylimpeded.

7. The combination of a pneumatic sand trap arranged to be operatedunder substantial in ternal air pressure when tlow therefrom be re`sisted; and a distensible nozzle through which said sand trapdischarges, said nozzle being arranged to be distended andy thus clearitself as an incident to the development oi' pressure said trap.

8. 'I'he combination of a train having a plurality of braked wheels; aplurality of pneumatic sand traps, said traps corresponding to diilerentwheels, and each arranged to be operated i d under substantial internalairpressure when ow therefrom is resisted; distensible sanding nozzlescorresponding to .the vvarious traps and through which such trapsdeliver said4 to the wheels, ,said nozzles beingv arranged to be dis-vtended and hence each to clear 'itselfjas .an incident to thedevelopment of pressure in a corresponding trap; ,andameans fordelivering air under pressure to all said traps simultaneously.

9. The combination of a train having a plurality of braked wheels;a'plurality of pneumatic-sand traps, said traps corresponding todifferent wheels, and each arranged to be op erated under substantialinternal air pressure when ilow therefrom is resisted; ldistensiblesanding nozzles corresponding to the various traps and through whichsuch traps deliver sand to the wheels, said nozzles being arranged to bedistended and hence each to clear itself as an i sanding nozzle; meansfor supplyingair under pressure simultaneously to said clean-out con-.nection and to said air nozzle to initiate sanding, and for thenterminating the supply of air to the clean-out connection; and pressureoperated means operated by pressure of air supplied to the air nozzleand serving to isolate said trap from said source.

11. A sand trap comprising in combination a body having a lower chamberhavinga discharge opening and a crest over which sand may vflow to thedischarge opening, and an upper chamber having a supply connection and apassage for delivering sand from the upper to the lower chamber inposition to be arrested by the crest; connections for supplyingclean-out air to both chambers simultaneously; jet means for stirringvsand in the lower chamber for causing it to ow over the crest; jet meansfor propelling sand through said discharge opening; pressure opereratedclosing means receive air simultaneously from one connection which isdistinct from the clean-out connection, the clean-out connection beingof relatively larger flow capacity.

14. The combination defined in claim ll-in which the stirring jet isldirected across the upper portion of the lower chamber toward thepassage from the upper to the lower chamber and in a direction away fromthe crest, and the propelling jet is directed substantially axially intosaid discharge opening, both jets being fed by a single connection.

15. I'he combination defined in claim 1i in which the pressure operatedsupply closing means comprises a valve, one element of which includes adistensible pocket serving to permit retreat of the sand as the valvecloses.

16. 'I'he combination of a sand supplying means; a sand-trap-comprisinga body having a lower chamber formed with a discharge opening and acrest over which sand may iiow to the discharge opening, and an upperchamber normally in free lcommunication with said supplying means, andhaving a discharge opening for delivering sand to the lower chamber inposition to be arrested by said crest; a large capacity cleanoutconnection for delivering air to both said chambers simultaneously; twoiet nozzles, one for directing stirring air into the lower chamber, andthe other for directing a propelling jet through said discharge opening;a pressure operated interceptor for isolating the sand trap from thesand supplying means; a second connection for supplying air underpressure to said iet nozzles and pressure operated interceptor; andmeans for supplying air simultaneously to said connections and thenterminating the supply to the rst-named connection while continuing thesupply to the second connection.

17. The combination of a sand supplying means; a sand-trap comprising abody having a lower chamber formed with a discharge opening and a crestover which sand may flow to the discharge opening, and an upper chambernormally in free communication with said supplying means, and having adischarge opening for delivering sand to the lower chamber in positionto be arrested by said crest; a clean-out connection for delivering airto both said chambers simultaneously; two :let nozzles. one fordirecting stirring air into the lower chamber, and the other fordirecting a propelling jet through said discharge opening; a pressureoperated interceptor for isolating the sand trap from the sand supplyingmeans; a second connection for supplying air imder pressure to said jetnozzles and pressure operated interceptor; means for supplying airsimultaneously to said connections and then terminating the supply tothe iirst-named connection while continuing the supply to the secondconnection; and a pressure deformable self-clearing nozzle connectedwith the discharge opening o! said lower chamber and arranged todischarge sand to a point of use.

18. A sanding mechanism comprising in combination a sand trap includinga body having a lower chamber provided with a discharge opening and acrest over which sand may iiow to the discharge, and an upper chamberhaving a supply connection and a passage for delivering sand from theupper to the lower chamber in position to be arrested by the crest;connections for supplying air to both chambers simultaneously, saidconnections including a relatively large pressure-equalizing passageconnecting said chambers; a distensible nozzle through which said trapdischarges, said nozzle being arranged to distend and clear itself ifsubjected to abnormal internal pressure; jet means for feeding sand oversaid crest through said discharge to said nozzle; means for sealing saidsupply connection; and means for operating said sealing means, andsupplying air under pressure toV said large capacity connections atleast during the initial portion of the sanding operation, and forsupplying air under pressure to said jet means during the sandingoperation.

19. The combination of a sand feeding device and a sand interceptingvalve adapted to seal air-tight, said valve comprising a. seat elementand a valve element movable relatively toward and from one another, theseat element being resilient and affording a distensible pocket intowhich sand trapped between the two elements may be forced and the valveelement including a resilient bulb distensible upon admission of pres-`sure iiuid thereto to cause closure of said valve element against theseat element.

20. The combination of a source of sand; a sand trap connected to be fedthereby; a sanding nozzle to which said trap delivers sand; a clean-outconnection; at least one air nozzle for pneumatically delivering sandfrom said trap to said sanding nozzle; means for supplying air underpressure simultaneously to said clean-out connection and to said airnozzle to initiate sanding, and for then terminating the supply of airto the clean-out connection; and pressure operated means serving toisolate said trap from said source and arranged to be controlled by saidairsupplying means.

2i. The combination of sand supplying means; a sand trap comprising abody having a chamber arranged to be fed by said supplying means; andhaving a discharge opening and a crest over which sand may be caused toilow to the discharge opening; a clean-out connection for delivering airunder pressure to said chamber; two iet nozzles, one for directing airto propel sand over said crest and the other for directing a propeilingjet through said discharge opening; a second connection for directingair under pressure to said nozzles; a pressure-operated interceptorarranged to be actuated by pressure developed in one of said connectionsand serving when active to isolate said chamber from said sand supplyingmeans; valve means operable to supply air under pressure simultaneouslyto both said connections and then to terminate the supply to the firstvwhile continuing the supply to the second; and a pressure-deformableself-clearing nozzle connected with said discharge opening and arrangedto discharge sand to the point f use.

CHARLES A. CAMPBEIL. LEWIS A. SAFFORD.

